Carbon holder



F. SPALCSS CARBON HOLDER May 15, 1934.`

Filed April 5, 1932 Patented May 15, 1934 UNITED STATES PATENT OFFICE CARBON HOLDER New York, N. Y.

Application April 5, 1932, Serial No. 603,314

2 Claims.

My invention relates to a carbon holder for arc light carbons and more particularly of the type as used in projecting apparatus for motion pictures.

5 As is well understood, the commercial carbon is furnished in pieces of two to three feet in length and such a piece is mounted in the feeding device of the projector and is automatically fed at the rate required by the combustion at the arc. To prevent overheating, the feeding device is placed at an appreciable distance from the point of combustion and when the carbon has been consumed to an extent, that only the piece extending from the feeding device to the are, re-

mains, a new carbon must be inserted and the aforesaid piece is discarded.

lt is the object of this invention to provide means for salvaging the greater part of the short pieces of carbon that now can not be used, by

providing a carbon holder on which these pieces can be mounted and which can be inserted in the feeding device of the projector and fed, the same as a piece of carbon. By these means, all, but a very short piece of carbon, can be used, thereby appreoiably reducing waste and cost of operation.

Fig. 1 is a view of the device as assembled for use.

Fig. 2 is a longitudinal section through the center.

Fig. 3 is an end view.

The cylindrical body 1 is of the same diameter as the carbon for which it is intended, so that it will t into the feeding mechanism of the projector and it is hollow and internally threaded at both ends. A gripping member 2 is threaded up to the shoulder 3 to t into one end of the body member and in order to facilitate the detaching or unsorewing of the gripping member, when it has become worn from the heat, the body member is slotted, so that it is slightly yielding. The gripping member is made of heat resisting material and the extension 4 thereof is grooved or threaded as shown, to provide teeth 5 and it furthermore is slotted, so that it can be expanded to force the teeth outward into the carbon. The pieces of carbon can be drilled out to fit over the extension 4, in any suitable manner, or the carbon can be moulded with the hole in it. To expand the gripping member, an expanding needle 6 is provided and extends through the body member, into the gripping member. The end of the gripping member has a small hole and a larger hole extends through the main body thereof and a taper shoulder 7 connects the two holes. The expanding needle has a tapered point 8 and a threaded portion 9, which screws into the rear end of the body member and to expand the gripping member, the needle is screwed into the body member, so that the point 8 presses against the shoulder 7 of the gripping member, thereby expanding the extension 4 and forcing the teeth into the carbon. To prevent too much expansion of the gripping member and thereby cracking of the carbon, the threaded portion of the needle terminates against a shoulder or enlarged portion 10, so that when the needle is screwed in against the shoulder, the gripping extension is properly expanded.

What I claim is:

1. A carbon holder having an extension adapted to be inserted into the carbon; slots in the extension, to adapt it for expansion to grip the carbon; an expanding member, to expand the extension and a stop on the expanding member, to limit the expansion, to prevent breakage of the carbon.

2. A carbon holder, comprising a tubular body member; a gripping member detachably mounted on one end of the body member; slots in the gripping member, to adapt it to be expanded for gripping; teeth in the gripping member to grip the carbon; slots in the body member, to permit a slight expansion thereof, to ease the detaching of the gripping member; an expanding member mounted in the tubular body member and adapted to be manually operated to expand the gripping member and a stop to limit the movement of the expanding member, substantially as shown and described.

FRANK SPALOSS. 

